1378669 has 2 divisors, whose sum is σ = 1378670. Its totient is φ = 1378668.

The previous prime is 1378639. The next prime is 1378673. The reversal of 1378669 is 9668731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1322500 + 56169 = 1150^2 + 237^2 .

It is a cyclic number.

It is not a de Polignac number, because 1378669 - 2⁷ = 1378541 is a prime.

It is a super-2 number, since 2×1378669² = 3801456423122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1378639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 689334 + 689335.

It is an arithmetic number, because the mean of its divisors is an integer number (689335).

2^1378669 is an apocalyptic number.

It is an amenable number.

1378669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1378669 is an equidigital number, since it uses as much as digits as its factorization.

1378669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 40.

The square root of 1378669 is about 1174.1673645609. The cubic root of 1378669 is about 111.2978231459.

The spelling of 1378669 in words is "one million, three hundred seventy-eight thousand, six hundred sixty-nine".